1. Field of the Invention
The present invention relates to an integrated circuit and related controlling method, and more particularly to prevention of leakage current in an integrated circuit and the related method.
2. Description of the Prior Art
When an integrated circuit is implemented and installed in a circuit board, the plurality of output pins of the integrated circuit are connected to the plurality of input pins of another integrated circuit. Furthermore, the output pins of the integrated circuit can also be utilized to receive a set of predetermined bit values for initializing the integrated circuit when the circuit system on the circuit board is powered up. Practically, the output pins of the integrated circuit are connected to a plurality of resistors in parallel, respectively. For example, when the circuit system is powered up, and if the bit value arranged for an output pin is 1, then the corresponding resistor is controlled to couple between the output pin and a supply voltage. On the other hand, if the bit value arranged for an output pin is 0, then the corresponding resistor is controlled to couple between the output pin and a ground voltage. Accordingly, the plurality of output pins of the integrated circuit is able to receive a set of predetermined bit values for initializing the integrated circuit when the circuit system is powered up. Then, after the circuit system is powered up, the output pins of the integrated circuit are returned to their original functions, i.e., outputting the signals generated by the integrated circuit. However, the above-mentioned resistors may still connect to the output pins respectively when the circuit system operates in the normal operational mode. Then, if an output voltage level at one output pin is opposite to the voltage level of the predetermined bit value when the circuit system is powered up, the resistor connected to the output pin may induce a current when the circuit system operates in the normal operational mode. More specifically, if the predetermined bit value of one output pin is 0 (i.e., a resistor is controlled to couple between the output pin and the ground voltage), then a leakage current will be induced to flow from the high voltage level to the ground voltage via the resistor when the idle voltage level of the output pin is the high voltage level. Therefore, the conventional output pin of the circuit system may induce a leakage current when the output pin is in the idle mode or the normal operational mode.